What does fast metabolism mean?
Your body is constantly using energy to function, whether you’re exercising, walking, or watching TV on the couch. Even if you are inactive or sleeping, your body is still using energy to keep your heart beating, maintain respiration, and rest and repair the body.
The ultimate source of your body’s energy comes from the food that you eat, which then gets broken down into different chemicals and nutrients during the digestion process and converted into energy. Your metabolism determines how your body uses that energy to maintain normal functioning. Your basal metabolic rate is the baseline amount of energy your body needs for normal resting functions like breathing and maintaining stable body temperature.
You may be surprised to learn that up to 80 percent of the energy your body uses in a day is used in its resting state, and between 10 and 20 percent is used in normal day-to-day activities like walking. Approximately 5–10 percent of your body’s energy is used in the digestion process.